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Finding the Fourth Proportional to 520, 780 and 491.14

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Solution

The fourth proportional to 520, 780 and 491.14 is: 736.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    520 : 780 = 491.14 : x
  2. Step 2: Convert to fraction form
    520/780 = 491.14/x
  3. Step 3: Cross multiply
    520x = 780 × 491.14
  4. Step 4: Simplify right side
    520x = 383,089.20
  5. Step 5: Solve for x
    x = 383,089.20/520
  6. Step 6: Final answer
    x = 736.71

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.